Danfoss S90 P Installation guide

Brand: Danfoss

Model: S90 P

Type: Installation guide

Danfoss S90 P is a variable pump designed for use in mobile hydraulic systems. It features a charge pressure relief valve that can be adjusted externally to optimize system performance. The pump is capable of delivering flow rates up to 100 GPM (380 L/min) and pressures up to 3500 PSI (240 bar). It is suitable for use in a wide range of applications, including construction, agriculture, forestry, and mining.

CHARGE PRESSURE

RELIEF VALVE

ADJUSTMENT

The following procedure explains how to check and adjust the charge pressure relief

valve.

Warning

The following procedure

may require the ve hicle/

machine to be disabled

(wheels raised oﬀ the

ground, work function

disconnected, etc.) in order

to prevent injury to the

technician and by standers.

Take necessary safety

precau tions before moving

the vehicle/machine.

Listed pressures assume a pump speed

of 1500 min

-1

(rpm). At higher pump

input speeds (with higher charge ﬂows)

the charge pressure will rise over the

rated set ting.

Charge pressure ranges

Model code Measured charge pressure*

18.1 – 21.7 bar

[262 –315 psi]

22.0 – 26.9 bar

[319 – 390 psi]

25.8 – 30.7 bar

[37.4 – 44.5 psi]

* This is the actual charge pressure port gauge

reading minus the case pressure port gauge

reading.

Charge pressure gauge port M3

K90

Adjusting screw

K10

Lock nut

Case drain port L1

52 N•m [39 lbf•ft]

0 - 10 bar [0 - 100 psi]

1 1/16-12

115 N•m [85 lbf•ft]

0 - 50 bar [0 - 1000 psi]

9/16-18

23 N•m [17 lbf•ft]

P106 162E

See appropriate table

Charge pressure relief valve

1. Install a 50 bar [1000 psi] pressure gauge in the pump charge pres sure gauge port

(M3). Install a 10 bar [100 psi] gauge to measure case pres sure (tee into L1 or L2 or

use servo gauge port M4 or M5). Operate the system with the pump in neutral (zero

displacement) when measuring pump charge pressure.

2. The table shows the acceptable pump charge pressure range for some charge relief

valve settings. These pressures assume 1500 min¯¹ (rpm) and a reservoir temperature

of 50°C [120°F], and are referenced to case pressure.

11085721 • Rev AB • September 2013 1

Service Kit Instructions

Series 90 variable pumps

Charge pressure relief valve adjustment

3. Later production Series 90 pumps have an external screw-adjustable charge

pressure relief valve. Loosen locknut (K10) and turn the adjusting screw (K90) using a

screwdriver or 1/2 in. hex wrench to adjust charge pres sure setting.

Lock nut wrench size

Frame size Wrench size

030 – 100 1-1/16 inch

130 – 250 1-5/8 inch

4. Clockwise rotation of the plug increases the setting and counterclockwise rotation

decreases the setting (at a rate of approximately 3.9 bar [50 psi] per turn). Torque

lock nut to 52 N•m [39 lbf•ft].

5. Once you achieve the desired charge pressure setting, remove the gauges and plug

the ports.

CHARGE PRESSURE

RELIEF VALVE

ADJUSTMENT

(continued)

11085721 • Rev AB • September 2013 2

Danfoss S90 P Installation guide

Danfoss S90 P Installation guide

Danfoss S90 P Installation guide

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